chore: bump clean-css from 4.2.4 to 5.2.4

Bumps [clean-css](https://github.com/clean-css/clean-css) from 4.2.4 to 5.2.4.
- [Release notes](https://github.com/clean-css/clean-css/releases)
- [Changelog](https://github.com/clean-css/clean-css/blob/master/History.md)
- [Commits](clean-css/clean-css@v4.2.4...v5.2.4)

---
updated-dependencies:
- dependency-name: clean-css
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

package-lock.json

@@ -89,7 +89,7 @@
     "api-viewer-element": "^0.6.4",
     "cem-plugin-module-file-extensions": "^0.0.2",
     "cem-plugin-readonly": "^0.0.2",
-    "clean-css": "^4.2.1",
+    "clean-css": "^5.2.4",
     "compression": "^1.7.4",
     "dedent": "^0.7.0",
     "dotenv": "^16.0.0",